1. Field of the Invention
This invention relates to the treatment of heartworms or adult filaria in the heart and circulatory systems of dogs. More particularly, the invention relates to a combined preventative treatment and therapeutic treatment for dogs infested with adult filaria by using vasoconstrictors and bronchial dilators, as well as cardiac and sympathetic stimulants to counteract the effects of therapeutic treatment with diethylcarbamazine. Since it is speculated that the treatment of adult filaria with diethylcarbamazine results in the release of a toxin which causes the body to secrete acetylcholine, a chemical which acts to produce massive vasodilation and bronchial constriction in the animal, treatment of the adult filaria requires application of both preventative and therapeutic medicine. The preventative treatment is designed to use certain vasoconstricting, bronchial dilating and/or cardiac and sympathetic stimulant medication such as prednisone, ephedrine, digoxin and dextroamphetamine sulfate to counteract the undesirable vasodilation and bronchial constriction with resulting cardiac weakening in dogs which are treated with the diethylcarbamazine.
The adult heart worm parasite or "filaria" slowly and painfully kills hundreds of thousands of dogs annually. The parasite is particularly prolific in the coastal states, where it is estimated that at least 80 percent of all dogs which remain outside in mosquito-infested areas will have an infestation of heartworms before they reach three years of age. None of the currently used veterinary treatments are highly effective and safe, and most cause severe pain, swelling and in some cases, necroses of the tissues.
2. Description of the Prior Art
Diethylcarbamazine has been used for years under a variety of trademarks such as "Caricide", a trademark of the American Cyanimid Company, for the treatment of adult filaria or "filiariasis" in dogs. Caricide was used during Word War II to treat filiariasis in human patients in the south pacific theatre where infestation became a problem in American troops in that area. Diethylcarbamazine was used throughout the 1950's and 1960's by veterinarians as a successful treatment of healthy dogs for infestations of dirofilaria immitis, which is the most common species of adult filaria infecting dogs in the coastal United States. Sometime after the era of the 1960's, Caricide was discontinued due to complaints that various side effects and occasional deaths occurred from its use in heavily affected dogs having large numbers of worms in the heart. This supposed drug-sensitivity reaction was noted to be more prevalent in weak and emaciated dogs which were subjected to long-standing stress from the infestataions and it was observed to only occurr in a small percentage of those dogs treated.
U.S. Pat. Nos. 2,467,893, 2,467,894, and 2,467,895, dated Apr. 19, 1949, to Kushner, el al, U.S. Pat. No. 2,643,255, dated June 23, 1953, to Gustave, et al and U.S. Pat. No. Re. 23,701, dated Aug. 18, 1953, to Stewart, et al, disclose the use of carbamyl compounds as treating agents for filariasis in veterinary practice. U.S. Pat. No. 4,172,118, dated Oct. 23, 1979, to Baetz, discloses the use of diphenylamine as a detoxicant for drugs administered to animals.
I have found through extensive experience and observation in using the chemical Caricide or diethylcarbamazine, that upon absorption into the bloodstream of a dog and upon making contact with adult heartworms in the heart of the dog, the diethylcarbamazine causes release of a toxin by the heartworms into the bloodstream. This toxin causes the parasympathetic system of the dog to produce acetylcholine, which, in turn, causes massive vasodilation and bronchial constriction in the dog. This condition produces a sudden fall in blood pressure, resulting in respiratory depression, heart failure and death from shock, a syndrome which is similar to the effect caused by a bee sting or other toxic insect sting or bite. Some animals are hypersensitive to this toxin released by the heartworms and death occurs rapidly after treatment by the diethylcarbamazine. If the animal is not hypersensitive to the toxin and is not unduly affected by the massive vasodilation and bronchial constriction caused by the acetylcholine it will recover, since the adult heartworms are destroyed by contact with the diethylcarbamazine. I have noted that dogs which exhibit this hypersensitivity to the toxin released by the heartworms upon contact with the diethylcarbamazine have been saved by injections of adrenaline and atropine immediately after the reaction took place. Accordingly, the incorporation of anti-reactant medicines by injection, as well as in a capsule or tablet with the diethylcarbamazine on a time-release basis, will control the undesirable side effects resulting from massive vasodilation and bronchial constriction which causes weakening of the heart due to the toxin released by the adult heartworms and the acetylcholine produced by the body as a result of this toxin release. Specifically, it has been found that medications such as ephedrine, digoxin, dextroamphetamine sulfate and prednisone can be used as vasoconstrictors, bronchial dilators and cardiac and sympathetic stimulants, as well as anti-inflammatory agents, to counteract the effect of treating adult heartworms with diethylcarbamazine in a capsule or tablet dosage structure.
Accordingly, it is an object of this invention to provide a new and improved method and dosage structure for treating heartworms or filiariasis in dogs or other animals by initially pretreating the dogs by injection, tablets or capsules to effect vasoconstriction and bronchial dilation and subsequently introducing diethylcarbamazine into the blood stream for destroying the heart worms.
Another object of this invention is to provide a new and improved method for treating animals which are susceptible to filiariasis, by the steps of initially pretreating the animal with vasoconstrictors, bronchial dilators and cardiac and sympathetic stimulants and subsequently treating the adult heartworm condition with diethylcarbamazine.
Yet another object of the invention is to provide a method for treating dogs afflicted with filiarasis, which method includes the steps of administering ephedrine, digoxin, dextroamphetamine sulfate and prednisone to serve as vasoconstrictors, bronchial dilators, cardiac and sympathetic stimulants and anti-inflammatory agents, respectively, and subsequently treating the animal with diethylcarbamazine to kill the heartworms.
Yet another object of this invention is to provide a new and improved solid dosage structure for treating animals which are subject to filariasis, which solid dosage structure is characterized by one or mroe pretreatment layers of a vasoconstrictor, bronchial dilator and cardiac and sympathetic stimulant and an inner, time-release treatment layer of diethylcarbamazine for killing the infestation of heartworms.
A still further object of the invention is to provide a new and improved solid dosage structure for treating filiariasis, which dosage structure is characterized by an outer coating of a palatable material such as sugar or the like, an inner coating of mixed ingredients which include a vasoconstrictor, bronchial dilator, cardiac and sympathetic stimulant and anti-inflammatory medication such as, for example, ephedrine, digoxin, dextroamphetamine sulfate and prednisone and an inner core of diethylcabamazine for killing the heartworms.
Another object of the invention is to provide a new and improved capsule or spansule dosage structure for treating filiariasis, which spansule is characterized by discrete pellets, beads or elements of a vasoconstrictor, bronchial dilator, cardiac and sympathetic stimulant and anti-inflammatory agent such as ephedrine, digoxin, and dextromphetamine sulfate and prednisone and a time release element or elements of diethylcarbamazine for killing the heartworms.